1. Field of the Invention
The invention relates to a semiconductor device and a manufacturing method thereof, and more particularly, to an image sensor and a manufacturing method thereof.
2. Description of Related Art
A complementary metal-oxide-semiconductor (CMOS) image sensor has a simple driving method and can implement a plurality of scanning methods, and is therefore extensively applied in imaging products such as security monitoring, digital cameras, toys, mobile phones, and video phones. In general, the image sensor includes a pixel array formed by the arrangement of a plurality of pixels, and each of the pixels is activated when receiving light. In the current trend of miniaturized image sensors, the spacing between pixels is reduced as a result. In this way, light incident to the image sensor generates severe optical scattering noise between pixels, that is, light originally to be received by a first color pixel may be received by a second color pixel due to light diffraction effect, thus causing the quantum efficiency (Q.E.) and the light sensitivity of each of the pixels to be worse, and causing the optical crosstalk between the pixels to be worse. Therefore, the spatial resolution and the overall sensitivity of the image sensor are reduced, and color mixing effect is generated, and therefore image noise is caused.
It can therefore be known that, in the current trend of miniaturized devices, how to increase the sensitivity of pixels under reduced size is one focus of study of various industries.